Nucleic acid molecules encodng a cathepsin L-like cysteine protease

Abstract

Compositions and methods for protecting a plant from an insect pest are provided. In particular, nucleic acid sequences encoding insect protoxins modified to comprise at least one proteolytic activation site that is sensitive to a plant protease or an insect gut protease are provided. Cleavage of the modified protoxin at the proteolytic activation site by a protease produces an active insect toxin. Methods of using the modified insect protoxin nucleic acid sequences and the polypeptides they encode to protect a plant from an insect pest are provided. Particular embodiments of the invention further provide modified insect protoxin compositions and formulations, expression cassettes, and transformed plants, plant cells, and seeds.

1. An isolated nucleic acid molecule comprising a nucleotide sequence that encodes a polypeptide having proteolytic activity, wherein said nucleotide sequence is selected from the group consisting of:
 (a) the nucleotide sequence set forth in SEQ ID NO:3; 
 (b) a nucleotide sequence encoding the amino acid sequence set forth in SEQ ID NO:4; 
 (c) a nucleotide sequence having at least 95% sequence identity to the nucleotide sequence set forth in SEQ ID NO:3; and 
 (d) a nucleotide sequence encoding a polypeptide having at least 95% sequence identity to the amino acid sequence set forth in SEQ ID NO:4. 
 
     
     
       2. A vector comprising the nucleotide sequence of  claim 1 . 
     
     
       3. An expression cassette comprising the nucleotide sequence of  claim 1  operably linked to a promoter that drives expression of the nucleotide sequence. 
     
     
       4. A host cell comprising a nucleotide sequence of  claim 1 . 
     
     
       5. A method for making a recombinant protein encoded by the polynucleotide of  claim 1 , wherein the method cultures the host cell of  claim 4  under conditions in which the polypeptide is produced.